The invention relates to improvements in a method and means for indicating leakage through the wall of a vessel.
To indicate leakage through a fraction of the wall of a vessel, such as a joint or seam made by soldering, gluing or welding, it is known to delimit a narrow closed space connected to a pressure measuring instrument at one side of the wall fraction to be tested, whereupon an increased gas pressure is caused to act on the opposite side of the wall of the vessel. Leakage through the wall fraction may then be seen as a reading on the measuring instrument.
However, a reliable leakage test may be made quite impossible, if the wall of the vessel is sufficiently resilient to be a little deformed by the pressure applied. In such a case it has been necessary to use lower overpressure, which involves a slower testing. On the other hand, a very quick test is highly desirable, especially in mass production of simple and cheap vessels or containers such as radiators and fuel tanks for cars. Moreover, it is desired that the test may be carried out mostly automatically without a lot of manual work.